Bug 18535 - Clicking 'edit printer profile' in label creator causes software error

Bug 18535 - Clicking 'edit printer profile' in label creator causes software error

1) Go to Tools > Label creator
2) If you don't have a printer profile defined, create one.
3) Go to manage > Printer profiles
4) Click the 'edit' button on any of the profiles.
5) INTERNAL SERVER ERROR! "Can't use string ("fields") as a HASH ref
while "strict refs" in use at /usr/share/koha/lib/C4/Creators/Lib.pm
line 147"
6) Apply patch
7) Click the 'edit' button on any of the profiles.
8) Things work as expected

Bug reproduced, is fixed by this patch
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>